Newtown , Connecticut -LRB- CNN -RRB- -- Every time the door bell rings at Aidan Licata 's home , the 6-year-old fears the gunman has returned .

He worries the man in black fatigues and military-style vest who opened fire Friday on his Sandy Hook Elementary School classroom -- hitting his teacher and his fellow students -- has found him .

`` He still has n't internalized the fact this gunman , this bad guy , is gone , '' the boy 's mother , Diane Licata , said . `` He wants to know if there are more bad guys in the world , and I do n't know how to answer that for him . ''

For now , the Licatas have put a sign on the door asking people not to ring the bell .

As this south New England town of 27,000 prepares to mourn the 20 children and six adults killed in the school shooting , parents of the youngest survivors are struggling to cope with the aftermath of a massacre that will require many of them to break the news to their child of the death of a teacher or a friend .

`` The children eventually will learn about their friends and their teacher , and others that they know . We need to be able to explain to them as best we can , '' Robert Licata , the boy 's father , said .

Aidan does n't know that his teacher , Victoria Soto , is among the dead . He also does n't know some of his friends have been killed .

Opinion : Slow down , listen to kids

The morning inside the school , when the gunfire started , Aidan said it sounded like `` falling hammers . ''

His teacher , Ms. Soto , moved her first grade students to the other side of the room . Moments later , the gunman -- identified by authorities as 20-year-old Adam Lanza -- was in the doorway .

Soto positioned herself in front of the students , and the gunman shot her , Aidan told his parents .

Aidan and the children had always been told during school drills and by his parents to run if he saw somebody with a gun . So that 's what he did .

`` They ran past the guy . He standing in the doorway , and they just ran right past him , '' the boy 's father said .

Aidan and the boys ran toward the front door , out of the building and then toward the main road where a woman stopped , picked them up and drove them to the police station .

`` He loved his teacher . ... I think he 's trying to reassure himself that she 's going to be OK , '' Aidan 's mother said . `` He keeps saying ' I really hope she is OK . He knows that that she 's been hurt . He knows the kids he saw getting shot . ''

Nick and Laura Phelps also are struggling with what to tell their two children , a first-grader and a third-grader .

They , like many of the parents , were alerted to a possible problem at the school by the district 's robocall that instructed them to go to the fire station .

There , they found their children .

`` When I saw those teachers , I locked eyes with them separately . If I could go back , I would embrace them , '' Nick Phelps said , `` because I had no idea what they had gone through . ''

Phelps and his wife planned to attend counseling services being offered in Newtown , and the couple also are seeking guidance from their church pastor .

`` We 're definitely going to talk to counselors , '' Nick Phelps said .

By Saturday night , the couple was fairly certain that their children were aware at the least of some of the developments .

`` I think they do know more than they let on , '' Laura Phelps said . `` We are going to have to learn what to say before we say it .

The Phelps did not want the names of the children out in the public .

Even those charged with breaking the news to young family members struggled .

At the St. Rose of Lima Catholic Church , Father George Weiss was with the parents of a little boy as they told him his sister had been killed .

`` We just told a little boy about his sister , and he asked , ` Who am I going to play with now ? I have nobody to play with now . ' ''

`` Excuse me , '' he said as tears rolled down his face , `` it was just so hard . ''

CNN 's Kate Bolduan reported from Newtown , and Chelsea J. Carter from Atlanta . CNN 's Soledad O'Brien contributed to this report .

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Aidan Licata , 6 , saw the gunman shoot his teacher and fellow classmates

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He told his parents that initially the gunfire sounded like ` falling hammers '

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Counseling services are being offered to the parents of shooting victims